JPH09267949A - Picture image recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly reliable picture image recorder which is inexpensive and conveys a scanned body stably in the direction of auxiliary scanning without causing fluctuation in speed to record picture image information in a good condition. SOLUTION: When a scanned body which is conveyed upward comes out from a pair of rollers 21 on the upstream side, nip force of the pair of rollers 21 on the upstream side is changed over into smaller nip force than nip force of a pair of rollers 22 on the downstream side by a nip force variable mechanism section 50. Consequently, impact generated when the scanned body comes out from the pair of rollers 21 on the upstream side is reduced to transfer to the conveyance which is mainly based on nip force of the pair of rollers 22 on the downstream side. As a result, stable conveyance is done and it is possible to prevent the occurrence of unevenness in scanning.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image recording apparatus for scanning a sheet-shaped object to be scanned with a laser beam while sandwiching it between roller pairs and carrying it, and more particularly to performing stable scanning of the object to be scanned. As described above, the present invention relates to a technique for controlling the clamping force during transportation.

[0002]

2. Description of the Related Art As an image recording apparatus for obtaining a radiation image of a subject such as a human body, for example, a stimulable phosphor (stimulable phosphor) sheet which stores and records radiation image information is scanned with excitation light such as a laser beam. To generate a photostimulated luminescence light, input the image signal obtained by photoelectrically converting the photostimulated luminescence light, and inputting an image signal, and a laser beam modulated based on the image signal by the image recording device is used as a recording material such as a photographic photosensitive material. It is known to perform scanning while irradiating a sheet with light and perform exposure recording as a visible image. It is known that a CT scanner directly inputs a digital image signal to perform the same recording.

In the above image recording apparatus, as a specific scanning method, the photographic photosensitive material is mechanically conveyed in one direction by a pair of conveying rollers to perform sub-scanning and is deflected in a direction orthogonal to the conveying direction. The main scanning is performed by irradiating a laser beam, but the scanned object such as the photographic photosensitive material is accurately scanned at a constant speed in the sub-scanning direction during the recording scanning in order to record accurate image information. Need to be transported.

For this reason, as a mechanism for transporting the photographic light-sensitive material, nip rollers which are rotationally driven in pressure contact with each other are arranged on the upstream side and the downstream side in the transport direction, and recording scanning is performed between the two pairs of nip rollers. , Is generally adopted.

[0005]

However, when the object to be scanned such as a photographic photosensitive material is constantly in pressure contact with the nip roller pair at a constant pressure as described above, the object to be scanned is located behind the object to be scanned by the roller pair on the upstream side. When the edge comes out, the object to be scanned is impacted, the rotational speed unevenness of the drive roller is deteriorated, and the position of the laser beam on the object to be scanned is displaced, causing scanning unevenness on the image.

In order to solve this problem, Japanese Patent Publication No. 5-451
The technique disclosed in No. 08 makes it possible to open and close the space between the rollers of the roller pair by an actuator, and when the scanned object enters the space between the roller pairs (in this case, the impact is also a problem), In addition, a structure is proposed in which the impact between the rollers is eased by separating the rollers from each other by a distance greater than the thickness of the object to be scanned when the rollers come out from between the rollers.

However, if the nip roller is separated from the object to be scanned during the laser scanning as described above, the rear end side of the object to be scanned may be in an open state, causing fluttering and uneven scanning. When the object to be scanned is conveyed in the horizontal direction, the object to be scanned slidably contacts the guide by providing a guide or the like, so that the object to be scanned can be prevented from fluttering to some extent, but the device is made compact, etc. Therefore, in the case of the method of scanning the object to be scanned while conveying the object in the vertical direction, the weight of the object to be scanned does not always make sliding contact with the guide, and it is difficult to prevent uneven scanning.

The present invention has been made in view of the above-mentioned conventional problems, and alleviates the impact when the object to be scanned vertically conveyed comes out of the roller pair on the upstream side, so that the uneven scanning occurs. An object of the present invention is to provide an image recording apparatus capable of preventing the above. Further, in order to alleviate the impact when the scanned object comes out of the roller pair or plunges between the roller pair as described above, while maintaining a stable conveyance speed during the scanning of the scanned object, the scanning by the roller pair is performed. It is a mechanism that variably adjusts the gripping force of the body, and it is possible to more reliably prevent uneven scanning without causing vibration fluctuations and performing stable operation without giving load fluctuations to the scanned object. An object is to provide an image recording device.

[0009]

Therefore, in the invention according to claim 1, an upstream roller pair disposed upstream of the laser beam irradiation position and a downstream roller pair disposed downstream of the irradiation position of the laser beam, In an image recording device that holds a sheet-shaped object to be scanned and performs sub-scanning while conveying in the vertical direction, while varying the holding force of the object to be scanned, and performing main scanning by irradiating the laser beam to record an image, When the rear end of the scan target in the transport direction comes out of the upstream roller pair, the clamping force of the upstream roller pair is switched from the clamping force greater than the clamping force of the downstream roller pair to a small clamping force. To do.

That is, before the object to be scanned comes out of the upstream roller pair, the object to be scanned is mainly conveyed by the clamping force of the upstream roller pair, and when the object comes out of the upstream roller pair, the clamping force is weakened. The impact is reduced, and the conveyance is switched mainly to the nipping force of the downstream roller pair.
The invention according to claim 2 is characterized in that the clamping force of the downstream roller pair is kept constant.

The clamping force of the downstream roller pair is kept constant by the urging force of an elastic member or the like, and is smaller than the clamping force of the upstream roller pair before the scanned object comes out of the upstream roller pair, but the scanning object is retained. Sufficient for stable nipping, and after the object to be scanned comes out of the upstream roller pair, the nipping force is set so that the object to be scanned can be conveyed only by the downstream roller pair.

According to a third aspect of the present invention, a sheet-shaped object to be scanned is composed of an upstream roller pair disposed upstream and a downstream roller pair disposed downstream of a laser beam irradiation position. In an image recording device for recording an image by performing a main scan by irradiating the laser beam while making a sandwiching force of a scan target variable while performing a sub scan while sandwiching and conveying,
At least one of the rotational torque generating means for variably outputting the rotational torque and the upstream roller pair or the downstream roller pair, so that the driven roller can be freely pressed against the drive roller forming these roller pairs. A means for rotatably supporting the rotation shaft of the driven roller on the tip of a lever that is free to swing with respect to a fixed support shaft; A gripping force variable mechanism for variably controlling the gripping force of the roller pair pressing the driven roller against the driving roller by controlling the rotation torque of the rotation torque generating means. Is characterized by.

The rotation torque generated by the rotation torque generating means is converted into the rotation torque of the lever supporting the rotation shaft of the driven roller, so that the driven roller becomes a driving roller with a force proportional to the rotation torque of the lever. It is pressed. Therefore, by controlling the rotational torque generated by the rotational torque generating means, the pressing force of the driven roller against the drive roller, that is, the clamping force of the roller pair is controlled.

The invention according to claim 4 is characterized in that the rotating torque generating means is a rotary solenoid. The rotation torque is controlled by controlling the energization amount of the rotary solenoid. According to a fifth aspect of the invention, the means for converting the rotational torque generated by the rotational torque generating means into the rotational torque of the lever and transmitting the rotational torque to the rotational torque generating means is substantially perpendicular to the rotational axis of the rotational torque generating means. A link that is connected so as to extend in the horizontal direction, a shaft that engages with the tip end portion of the link and is vertically movable by swinging of the link around the rotation axis, and a driven roller that is connected to the lower end of the shaft. A connecting bar that extends parallel to the rotation axis of the connecting bar and that engages with the lever at both ends, and the lever swings around a fixed support shaft by the vertical movement of the connecting bar that is interlocked with the shaft of the roller pair. It is characterized in that the clamping force of is variable.

When the rotating shaft of the rotating torque generating means rotates, the link rotates around the rotating shaft and the tip of the link extending substantially horizontally swings in the substantially vertical direction. The shaft that engages with the part and the connecting bar that is connected to the lower end of the shaft move up and down. As a result, the lever whose ends engage with both ends of the connecting bar swings around the fixed support shaft, and the pressing force of the driven roller against the drive roller, that is, the clamping force of the roller pair is variably controlled.

According to a sixth aspect of the invention, in the image recording apparatus according to the first or second aspect, any one of the third to fifth aspects with respect to the upstream roller pair.
And a clamping force variable mechanism for switching the clamping force of the upstream roller pair by the clamping force variable mechanism.

The gripping force of the upstream roller pair is controlled to be smaller than that of the downstream roller pair by controlling the rotation torque of the rotating force generating means when the object to be scanned comes out of the upstream roller pair by the gripping force varying mechanism. It is possible to switch from a large clamping force to a small clamping force. Further, the invention according to claim 7 is characterized in that a direction changing guide for changing the direction of the scanned object to the laser scanning side is included on the downstream side of the downstream roller pair in the sub scanning direction.

The object to be scanned is guided by the direction changing guide from the part where the scanning is completed and is changed to the laser scanning side where the receive magazine and the like are placed. Further, in the invention according to claim 8, the upstream side roller pair and the downstream side roller pair each include a driving roller on the laser scanning side and a driven roller on the opposite side, and at least the upstream side roller pair in the vertical direction. Between the downstream roller pair, a rear guide which is arranged close to the side opposite to the laser irradiation surface from the vertical tangent line on the driven roller side of the upstream and downstream drive rollers and which guides the rear surface of the object to be scanned. It is characterized by including.

The rear surface of the object to be scanned, which is sandwiched between the pair of rollers, on the side opposite to the laser scanning side is along the guide surface of the rear surface guide disposed near the rear surface of the object to be scanned. Is guided while being maintained in the vertical state, and is nipped by the downstream roller pair from the front edge of the object to be scanned.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below. FIG. 1 shows a schematic configuration diagram of an image recording apparatus in the present embodiment. The operation of image recording on the object to be scanned will be described with reference to FIG. An image recording device 10 for obtaining a radiation image of a subject such as a human body is detachably mounted with supply magazines 11 and 12 and receive magazines 13 in two layers, and an X ray film or the like is provided in the supply magazines 11 and 12. A plurality of sheet-shaped photographic light-sensitive materials (hereinafter referred to as "scanned objects") are stored with the exposed surface facing downward. On the other hand, the receive magazine 13 sequentially stores the objects to be scanned after exposure and recording as described later.

Adjacent to the supply magazine 11 is a suction cup 11
a, a sheet-fed mechanism including a suction plate 12a is provided in the vicinity of the supply magazine 12, and the sheets are taken out one by one from the uppermost layer part and fed out to the transport mechanism. Here, the sheet-fed mechanism is a suction plate, but it may be a pickup roller such as a paper feed roller used in a copying machine. The transport mechanism is configured by a transport roller group and a guide roller group that are provided behind the supply magazines 11 and 12 and extend in the vertical direction and are provided on the transport path. It should be noted that the conveying roller conveys the object to be scanned while sandwiching the object to be scanned, and the guide roller is rotating, but only guides the object to be scanned.

For example, the object to be scanned taken out from the supply magazine 11 is conveyed in the direction of the arrow by the conveying roller 11b, is curved so as to be directed vertically downward along the guide 11c, and is then conveyed by the conveying rollers 11d and 14. Further, it is conveyed downward and reaches the guide roller 15. Meanwhile, Supply Magazine 12
The object to be scanned taken out from is conveyed by the conveying roller 12b in the direction of the arrow, is curved so as to be directed vertically downward along the guide 12c, and is further conveyed downward by the conveying roller 14 in the same manner as described above. Reach roller 15.

The object to be scanned, which is guided further downward by the guide rollers 15, stops once it reaches the lower layer of the apparatus. Under this condition, the hooks 16 are hooked on both ends of the front end of the object to be scanned, and the guide roller 15 reverses the direction of rotation so as to guide the object to be scanned upward, and the other guide rollers 17 , 18, 19 are also controlled to rotate in the same direction.

The latch claw 16 is a guide 16c extending in the vertical direction which receives a driving force from a rotary drive source such as a motor (not shown).
Since it is provided in a conveyance mechanism such as an endless belt arranged along the above, it has an upward conveyance force and switches back the object to be scanned to convey it upward. Note that the latch claw 16 is provided so that its disposition position can be adjusted back and forth in the transport direction of the object to be scanned, for example, by changing the screw tightening position.

The object to be scanned is a guide 16c and guide rollers 15,1.
Although it is guided vertically upward by 7, 18, 19 and reaches the exposure recording unit 20, speed control is performed so that the transport speed is reduced to a speed suitable for exposure recording. Regarding the transportation speed, except that the scanned object is transported at the exposure recording speed (recording speed), that is, the scanned object is the supply magazine.
Since it is possible to switch to high speed conveyance (conveyance speed) before being taken out from 11 and 12 and before reaching the exposure recording unit 20, and from when the exposure recording unit 20 records the image information until it is stored in the receive magazine 13, It is possible to reduce the total processing time.

When the object to be scanned is conveyed into the exposure recording section 20 and its tip reaches the recording position, a laser beam is emitted from the laser light source in the exposure section 30 and reflected by the mirrors 30a and 30b, and then the exposure recording is performed. The light enters the portion 20 and exposure recording is performed at the recording position. Here, the laser beam is modulated in advance based on image information obtained from a stimulable phosphor sheet or the like, and is mechanically sub-scanned in the transport direction by two pairs of upper and lower rotary rollers of the exposure recording unit 20 described later. The scanning mechanism is such that the exposed surface of the scanned object is deflected by a polygon mirror (not shown) or the like that rotates in a direction substantially orthogonal to the sub-scanning direction to perform main scanning.

2 and 3 are detailed block diagrams of the exposure recording unit 20, and FIG. 4 is a control timing chart of the exposure recording unit 20. The characteristic scan recording of the present invention will be described in detail with reference to FIGS. As a sub-scanning direction conveyance mechanism of the exposure recording unit 20, a drive roller 21a and a driven roller 21b that rotates along with the rotation of the drive roller 21a are provided in a pair (hereinafter, simply referred to as an upstream side) with respect to a conveyance direction of a scanned object. Side roller pair 21). Similarly, on the downstream side, the driving roller 22a and the driven roller 22b are also provided.
Are arranged in pairs (hereinafter, simply referred to as a downstream roller pair 22).

Here, the upstream roller pair 21 and the downstream roller pair 22 can be sandwiched by the scanned object with a proper frictional force without slipping, and in view of the stability of the transportation of the scanned object, a metal roller made of stainless steel. And a rubber roller made of rubber are suitable. In this embodiment, the driving rollers 21a and 22a are metal rollers and the driven rollers 21b and 22b are rubber rollers. The metal roller may be other than stainless steel in terms of hardness and cost.

The endless belt 26, which is biased by the tension roller 24 and has a constant tension, is driven by the drive rollers 21a, 22.
It is provided on pulleys 21c and 22c arranged on the rotation shaft of a, and the rotation drive unit 25 such as a drive motor is provided with a drive roller 21a.
By transmitting the rotational force to the drive rollers 21a and 22a, both are driven to rotate. Here, the driving force is transmitted not by the gear but by the belt such as the endless belt 26 in order to reduce the transmission of the vibration generated by the rotation driving unit 25 to the driving roller 22a. Is. Further, unlike the timing belt, the endless belt 26 does not have teeth and exclusively transmits the driving force by frictional force.
This is for avoiding the influence of backlash due to teeth, reducing vibration, and suppressing unevenness in rotation speed well. A resin belt or a metal belt is used as the endless belt 26, and tension is appropriately set depending on the material so that slip does not occur between the pulley and the endless belt.

According to the transport mechanism as described above, since the drive roller is arranged on the laser beam irradiation side, it is possible to dispose the rotation driving section 25 having a large outer shape inside the apparatus, and downsizing the entire apparatus. Can be realized. Especially the drive roller
This is suitable when using the rotary drive unit 25 that directly drives 21a. Further, the rotation driving unit 25 and the driving roller 21a
A deceleration system for decelerating the rotation speed to a desired speed may be provided between and.

When the sensor (not shown) detects the presence or absence of the object to be scanned before it reaches the exposure recording unit 20, the object to be scanned, which has been conveyed from below at a high conveying speed, is controlled at a low speed based on this. It At the same time, the rotation drive unit 25 transmits the rotational force to the drive roller 21a so as to be rotationally driven at the peripheral speed of the recording speed in the sub-scanning direction. The object to be scanned is the exposure recording unit 20.
Sensor A27 detects this, and outputs a detection signal to the clamping force varying mechanism unit 50 having a function described later. The gripping force varying mechanism 50 is configured as described later, and when the detection signal is input, as shown in FIG. 4, the gripping force (nip pressure) of the upstream roller pair 21 is changed from the open state or the slightly crimped state to the strong crimping state. It is gradually increased to the state and the carrying force of the scanned object is applied. Here, the reason why the clamping force is not suddenly increased is to suppress the occurrence of vibration due to the rapid change in the clamping force. The slight pressure bonding is a pressure set to the minimum pressure that does not cause the outer shape deformation of the rubber roller, and the upstream roller pair 21 is opened or slightly pressed before the sensor A27 detects the object to be scanned. The purpose is to prevent the outer shape deformation of the rubber roller.

At the time when the clamping force of the upstream roller pair 21 is strongly pressed, the front edge of the object to be scanned plunges into the upstream roller pair 21 and is conveyed at the recording speed while being clamped at the recording position. It is detected by the sensor B28. The detection signal of the sensor B28 is output to the exposure control unit 29, and the exposure control unit 29 controls the exposure unit 30 based on the detection signal so that a laser beam corresponding to the image information is emitted and the image information is output from the tip of the scan target. Is recorded.

It should be noted that, from the start of the rotational driving of the upstream roller pair 21 to the steady state, there are fluctuations such as uneven rotation due to the rising of the rotation of the rotational driving unit 25, and the scanned object is the upstream roller. When entering the pair 21, there may be a shock due to the rush resistance, but the upstream roller pair 21 and the recording position are separated so that the time required for the fluctuation due to the above-mentioned fluctuation and shock to converge can be gained. Since the distance is set, the irradiation position of the laser beam on the object to be scanned does not deviate from causing scanning unevenness.

In this way, the front edge portion of the scanned object, which is exposed and recorded with the image information on the scanned object, is projected into the downstream roller pair 22. -3
As proposed in No. 24880, since it is rotated with a constant clamping force with a gap smaller than the thickness of the scanned object,
The rush resistance when the scanned body rushes into the roller pair on the downstream side is small, and the generated impact can be reduced as much as possible. In addition, the clamping force of the upstream roller pair 21 is set to the downstream roller pair.
Since the main conveyance force of the scanned object is in the upstream roller pair 21, the slip is generated when the front edge of the scanned object enters the downstream roller pair 22 because it is stronger than the nip force of 22. The object to be scanned can be accurately conveyed in the sub-scanning direction and the image information can be recorded satisfactorily without any occurrence.

Further, the front edge of the object to be scanned is converted from the substantially vertical direction to the substantially horizontal direction by the direction changing guide 40 arranged on the downstream side of the sub-scanning section, and is conveyed while slidingly contacting the direction changing guide 40. To be done. The direction changing guide 40 has a radius-of-curvature portion 41 on the scanning surface side of the object to be scanned. A guide roller 43 is arranged downstream of the roller pair 22 on the downstream side in the sub scanning. This has the function of preventing the scanned object from tilting to the scanning surface side more than necessary when the scanned object is curved toward the scanning surface side by the direction changing guide 40, and is not shown in the apparatus. This prevents scratches and other damage that may occur when the product comes into contact with. This guide 43 may or may not be driven.

Switching of the clamping force of the upstream roller pair 21 when the rear end of the object to be scanned according to the present invention leaves the upstream roller pair 21 is performed after the sensor B28 detects the front edge of the object to be scanned. The holding force variable mechanism unit 50 is configured to determine the rear end of the object to be scanned according to the time measured by the timer, and can be appropriately set according to the length of the object to be scanned in the transport direction. It is possible. Also regarding the end of the recording of the image information, the timing at which the rear end of the scanned object passes the exposure position is set by the time measured by the timer after the sensor B28 detects the front edge of the scanned object. The irradiation of the laser beam is terminated after the rear end of the scan target passes through the exposure position.

The clamping force varying mechanism portion 50 of the upstream roller pair according to the present invention is constructed as shown in FIG. That is,
A rotary solenoid (rotational torque generating means) 51 that variably outputs a rotation torque according to a control signal from the rotary solenoid control unit 58 is provided, while the rotation shaft of the driven roller 21b of the upstream roller pair 21 is connected to the fixed support shaft 52a. The L-shaped lever 52, which freely swings around, is rotatably supported at the swinging end of the L-shaped lever 52 extending in the substantially vertical direction, and the rotational torque of the rotary solenoid 51 is rotated by the following conversion means. It is configured to be converted into torque. Although only one end (left end) of the driven roller 21b is shown in the drawing, the driven roller 21b is formed by being divided into a plurality of parts in the axial direction as shown, and the opposite end is It is supported symmetrically as well.

Explaining the converting means, a link 53 is connected to an output shaft 51a of the rotary solenoid 51 so as to extend in a horizontal direction at a right angle to the shaft, and the link 53 is provided.
A shaft 55 extending in the vertical direction is engaged with the tip of the shaft via an engaging member 54, and the shaft 55 is movable in the vertical direction by swinging the link 53 around the output shaft 51a. The engaging member 54 engages with the distal end portion of the link 53 through a groove that is long in the horizontal direction so as to allow horizontal sliding, and thus the shaft 55 receives a horizontal force. It prevents you from joining. A connecting bar 56 extending in parallel with the rotation axis of the upstream roller pair is connected to the lower end of the shaft 55 and is movable in the vertical direction in conjunction with the shaft 55.
The shaft 55 is connected to a substantially central portion of the connecting bar 56, that is, in the vicinity of the center of gravity, whereby the connecting bar 56 can be stably moved up and down while maintaining left-right balance. Both ends of the connecting bar 56 are driven rollers 21b of the L-shaped lever 52.
It is engaged with a long hole 52b formed in a swing end portion extending in a substantially horizontal direction different from the supporting side so as to allow horizontal sliding. Further, the adjustment screw 57 is used to adjust the vertical clearance between the connecting bar 56 and the L-shaped lever 52 so that the holding balance between the left and right can be adjusted. Also, the shaft 55
Is linearly moved by a linear bearing (not shown).

The output shaft 51 of the rotary solenoid 51
When a rotates, the shaft 55 and the connecting bar 56 move up and down via the link 53, and the L-shaped lever 52 rotates around the fixed support shaft, so that the driven roller 21b moves forward and backward with respect to the drive roller 21a. By controlling the rotational torque in the clockwise direction in the drawing of the output shaft 51a, the rotational torque of the L-shaped lever 52 is proportionally controlled, and the clamping force of the upstream roller pair is controlled.

When the clamping force is set to the strongly pressed state, the rotary shaft 51a of the rotary solenoid 51 rotates to the position set by the control signal output from the rotary solenoid control unit 58, and the link 53 and the engaging member By 54,
The shaft 55 moves upward to lift the connecting bar 56. As a result, the L-shaped lever 52 rotates about the support shaft 52a, and the driven roller 21b presses against the drive roller 21a,
Use strong pressure.

Then, a control signal is output from the control unit 58 to the rotary solenoid 51 immediately before the rear end of the scanned object comes out of the upstream roller pair 21, and the rotary solenoid 51 is controlled.
The rotary shaft 51a of the L-shaped lever 52a rotates in the direction in which the shaft 55 is lowered to the set position, the connecting bar 56 moves downward, and
Rotates around the support shaft 52a, and the force with which the driven roller 21b is pressed against the drive roller 21a becomes weak (see FIG. 4). As a result, the upstream roller pair 21 is in a weakly pressure-bonded state, and the main conveyance of the scanned object moves to the downstream roller pair 22.
In this weakly pressed state, the driven roller 21b is the driving roller 21a.
However, the object to be scanned cannot be sandwiched and conveyed by itself. Driven roller 21b
Is rotating in contact with the object to be scanned, the rear end of the object to be scanned does not flutter. Further, since the clamping force is switched by the torque control of the rotary solenoid 51, the operation of the clamping force variable mechanism unit 50 is extremely small, and the elastic member is damped as compared with when the elastic member is switched. The operation is stable because there is no influence or influence of vibration. By making the clamping force of the upstream roller pair 21 into a weakly pressure-bonded state, it is possible to suppress the load fluctuation that occurs when the rear end of the object to be scanned comes out of the upstream roller pair 21, and to prevent the rotational speed unevenness of the drive roller 21a. Since it is possible to keep the satisfactorily good condition and to prevent the rear end of the scanned object from fluttering, it is possible to obtain an image without scanning unevenness.

Further, in the present embodiment, the rotational torque can be transmitted to the left and right L-shaped levers in good balance by providing only one rotary solenoid, but the rotary solenoid having the maximum rotational torque of about 1/2 is used. It is also possible to provide two on the left and right sides and connect the rotary shaft of the L-shaped lever to the rotary shaft of the rotary solenoid for direct rotation.

Further, since the scanning object is curved toward the scanning surface by the direction changing guide 40, when the rear end of the scanning object comes out of the upstream roller pair, it bounces in the direction opposite to the scanning surface side and causes uneven scanning. However, in this embodiment, two pairs of driving rollers are provided between the upstream roller pair 21 and the downstream roller pair 22.
From the vertical tangent of 21a, 22a on the driven roller side, in the direction opposite to the laser beam irradiation surface, at a distance x of 1.0 mm or less, which is larger than the thickness of the object to be scanned, the rear guide 61 is vertically provided.
Are arranged to prevent the body to be scanned from bouncing.

Further, since the driven roller 21b is a split roller, even between the driving roller 21a and the driven roller 21b,
The back guide 61 can be inserted in the gap between the split rollers shown in FIG. For example, when the scanned object is an X-ray film and the thickness is 0.18 mm, two pairs of drive rollers 21a,
From the vertical tangent line of 22a (on the driven roller side), in the direction opposite to the laser beam irradiation surface, larger than 0.18 mm, 1.0 mm
The back guide 61 may be arranged at a position less than If the thickness of the object to be scanned is less than or equal to the thickness of the object to be scanned, it becomes difficult to convey the object to be scanned, and if it is more than 1.0 mm, the bounce of the object to be scanned cannot be sufficiently prevented, resulting in uneven scanning. There are cases. The rear end of the scan target is laser-scanned while being in sliding contact with the back guide 61 and is conveyed, so that an image without scanning unevenness can be obtained over the entire region of the scan target.

Further, in this embodiment, the downstream roller pair is
A scanning surface guide 62 is provided at a position close to the upstream side of 22 so as to closely face and oppose the guide surface of the back guide 61. The lower end, which is the upstream end of the scanning plane guide 62, is bent toward the laser scanning side. With the scanning surface guide 62, the front end of the object to be scanned can be reliably guided between the scanning surface guide 62 and the back surface guide 61 and guided to the downstream roller pair 22.

In this way, the laser beam irradiation ends when the rear end of the object to be scanned reaches the scanning position, and the rear end of the object to be scanned exits the downstream roller pair 22 and, at the same time, the direction changing guide 40. The nip roller 42b of the roller pair 42 arranged at the outlet of the roller is pressed against the driving roller 42a to convey the object to be scanned at high speed and store it in the receive magazine 13 for the next exposure recording.

As described above, in the present embodiment, the case of exposing and recording on a sheet-shaped photographic light-sensitive material such as an X-ray film has been described in detail, but the present invention is not limited to this and various kinds such as PS plates used for printing. The present invention can be applied to the photographic light-sensitive material, and other than the image recording device, any device that scans with a laser beam can be diverted.

[0048]

As described above, according to the first aspect of the invention, when the object to be scanned comes out of the upstream roller pair, the clamping force is switched to be smaller than the clamping force of the downstream roller pair. As a result, the impact when the scanned object comes out is alleviated, and after being ejected, it is stably conveyed by the nipping force of the downstream roller pair.

Therefore, scanning unevenness can be effectively prevented by the stable conveyance when the object to be scanned comes out of the upstream roller pair and also after it comes out. Before the object to be scanned comes out of the pair of upstream rollers, it is needless to say that the conveyance force is stably carried by the clamping force of the pair of upstream rollers to prevent uneven scanning. In this way, stable scanning can be performed from the time when the scanned object is clamped by the upstream roller pair to the downstream roller pair only. As a result, scanning from the scanning start to the scanning end of the scanning object is performed. It is possible to secure the period, and hence the scanning area of the scanned object as large as possible,
It is possible to perform scan printing without waste.

According to the second aspect of the present invention, if the clamping force of the downstream roller pair is appropriately set, the clamping force is kept constant, and only the upstream roller pair has a variable clamping force. With the configuration described above, the structure can be manufactured simply and at low cost, and the highly reliable configuration allows the highly-conveyed object to be transported and highly accurate scan recording.

Further, according to the third aspect of the present invention, by controlling the rotational torque of the rotational torque generating means, a clamping force proportional to the rotational torque can be applied to the roller pair, and the desired clamping force can be applied. The size can be easily controlled with high accuracy. Further, the clamping force can be made variable by a slight movement of the mechanism. For example, compared with a mechanism in which the elastic member is elastically deformed by the rotation of a cam to make the clamping force variable, the influence of the damping of the elastic member or Since no vibration is generated, the operation is stable and high clamping force control accuracy can be obtained.

Further, according to the fourth aspect of the present invention, by using the rotary solenoid as the rotational torque generating means, highly accurate rotational torque control can be performed by controlling the energization amount. Further, according to the invention of claim 5, the rotation torque generated by the rotation torque generating means can be converted into the rotation torque of the L-shaped lever while keeping the torque ratio substantially constant. The torque can be generated in proportion to the rotation torque of the rotation torque generating means, and the rotation torque can be controlled with high accuracy, and the clamping force of the roller pair can be controlled with high accuracy.

Further, by connecting the shaft to the central portion of the connecting bar, it is only necessary to provide one rotating torque generating means, so that the left and right L-shaped levers supporting both end portions of the rotating shaft of the driven roller are provided with a well-balanced rotating torque. It can be transmitted and can have a simple structure. Further, according to the invention of claim 6, an image recording apparatus having a configuration for switching the holding force when the scanned body comes out of the upstream roller pair is provided with a rotational torque generating means and a transmitting means for the rotational torque. By using the clamping force variable mechanism, the control at the time of switching the clamping force can be performed with high precision, and the occurrence of scanning unevenness due to the impact mitigation at the time when the scanning target is pulled out from the upstream roller pair is effectively generated. Can be prevented.

Further, according to the invention of claim 7, it is possible to change the direction of the object to be scanned, which has been scanned, to the laser scanning side by the direction changing guide and store it in the receive magazine or the like. The directional length can be shortened, the size can be reduced, and the operability is improved. Further, according to the invention of claim 8, the object to be scanned is conveyed while being maintained in the vertical state while being guided along the guide surface of the back guide on the back surface opposite to the laser scanning side. In the directional transport method, it is possible to prevent lateral shake of the object to be scanned and to improve scanning recording accuracy as much as possible.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a schematic configuration of an image recording apparatus according to this embodiment.

FIG. 2 is a cross-sectional view showing details of an exposure recording unit in the present embodiment.

FIG. 3 is a perspective view showing a configuration of a clamping force variable mechanism section in the present embodiment.

FIG. 4 is a control timing chart of the exposure recording unit according to the present embodiment.

[Explanation of symbols]

 11, 12 Supply magazine 13 Receive magazine 20 Exposure recording section 21 Upstream roller pair 22 Downstream roller pair 21a, 22a Drive roller 21b, 22b Driven roller 40 Direction change guide 50 Clamping force variable mechanism section 51 Rotary solenoid 52 L-type lever 53 Link 55 Shaft 56 Connecting bar 58 Rotary solenoid control section 61 Rear guide

Claims (8)

[Claims] 1. A sheet-shaped object to be scanned is nipped and conveyed in a vertical direction by an upstream roller pair disposed upstream of a laser beam irradiation position and a downstream roller pair disposed downstream thereof. In an image recording apparatus that records an image by performing main scanning by irradiating the laser beam while performing sub-scanning and varying the clamping force of the scanned object, a rear end of the scanned object in a transport direction is from an upstream roller pair. An image recording apparatus characterized in that, when it comes out, the clamping force of the upstream roller pair is switched from a clamping force larger than the clamping force of the downstream roller pair to a small clamping force. 2. The image recording apparatus according to claim 1, wherein the nipping force of the downstream roller pair is held constant. 3. A sub-scan is performed while a sheet-shaped object to be scanned is sandwiched and conveyed by an upstream roller pair disposed upstream and a downstream roller pair disposed downstream of a laser beam irradiation position. In an image recording apparatus that records an image by performing main scanning by irradiating the laser beam while changing the clamping force of the scanned object while performing the rotation torque generation means that variably outputs the rotation torque, and the upstream roller pair. Alternatively, the rotary shaft of the driven roller is swingable with respect to the fixed supporting shaft so that the driven roller can be pressed against at least one of the downstream roller pair against the drive roller forming the roller pair. And a means for rotatably supporting the tip of the lever, and a means for converting the rotational torque generated by the rotational torque generating means into the rotational torque of the lever. By controlling the rotational torque of the torque generating means, an image recording apparatus characterized in that a clamping force varying mechanism for variably controlling the gripping force of the roller pair presses to drive roller driven roller. 4. The image recording apparatus according to claim 3, wherein the rotating torque generating means is a rotary solenoid. 5. A means for converting the rotation torque generated by the rotation torque generating means into a rotation torque of a lever is connected to a rotation shaft of the rotation torque generating means so as to extend in a horizontal direction substantially at right angles to the rotation shaft. A link, a shaft that is engaged with the tip of the link and is movable in the vertical direction by rocking the link around the rotation axis, and a shaft that is connected to the lower end of the shaft and extends parallel to the rotation axis of the driven roller. A connecting bar that engages with the lever, and a vertical movement of the connecting bar that is interlocked with the shaft causes the lever to swing around a fixed support shaft so that the clamping force of the roller pair can be varied. The image recording device according to claim 3 or 4, wherein 6. The clamping force varying mechanism according to claim 3, which is provided for the upstream roller pair.
The image recording apparatus according to claim 1, wherein the clamping force variable mechanism switches the clamping force of the upstream roller pair. 7. A direction change guide for changing the direction of the object to be scanned to the laser scanning side is included downstream of the pair of downstream rollers in the sub-scanning direction, according to any one of claims 1 to 6. The image recording apparatus according to any one of items 8. The upstream roller pair and the downstream roller pair each include a driving roller on the laser scanning side and a driven roller on the opposite side, and at least the upstream roller pair and the downstream roller pair in the vertical direction. Between the upstream drive roller and the downstream drive roller from the vertical tangent line on the driven roller side, located close to the side opposite to the laser irradiation surface, and includes a back surface guide for guiding the back surface of the object to be scanned. The image recording apparatus according to any one of claims 1 to 7, which is characterized in that.